Injection and hemostasis site

ABSTRACT

A pad of elastomeric material having a softness of typically no more than about durometer 50 Shore 00. The pad may carry adhesive and/or a housing for adhering the pad to a surface, either manually, or by adhesive tape, or another strap. Such a pad exhibits hemostatic and leak prevention properties against needle puncture holes in the skin or the wall of a hollow medical device. Particularly, hemostasis may be prevented with low pressure application of the pad to the skin. The pad may be previously applied to the skin of the patient or a wall of a medical device such as tubing or a solution bag, and the needle may then penetrate both the pad and the skin or medical device wall, to make a resealable puncture with leakage reduction and hemostasis when the needle is withdrawn.

This is a continuation-in-part of U.S. patent application Ser. No.11/218,220, filed Sep. 1, 2005, and a continuation-in-part of U.S.patent application Ser. No. 10/943,106, filed Sep. 16, 2004.

BACKGROUND OF THE INVENTION

Generally, when the needle or catheter penetrates the skin for access toan artery, a vein, or a fistula as in hemodialysis, there is a certainamount of bleeding that takes place when it is removed. In blooddonation, for example, when the donor needle is removed, the donor isasked to elevate his or her arm and to press cotton gauze against theneedle penetration site for some minutes, until the wound has completelyclotted.

In the field of extracorporal blood processing such as hemodialysis,larger diameter needles, such as 15 gauge needles, are used rather thanthe smaller needles used for blood collection and blood sampling. Theblood pressure is higher due to the fistula's arterialized veinstructure, and the patient is anticoagulated for the extracorporealprocedure. Thus, when the needle is withdrawn, bleeding is morepronounced, and must be dealt with more rigorously, to avoid the loss ofa significant amount of blood through bleeding. Since hemodialysis inparticular is performed frequently on chronic patients, even small bloodlosses can add up, so that it would be desirable to minimize thebleeding to avoid the relatively small amount of blood that isconventionally lost when dialysis needles are withdrawn.

Generally, compression is used for a period of time after withdrawal ofany hollow bore needle, to achieve hemostasis. Typically, this is donewith absorbent gauze manually pressed over the cannulation site as soonas the needle is removed. As the gauze is absorbent, this method doesnot staunch bleeding, but merely creates a slowing of the blood leakageso the body's natural clotting mechanisms can eventually take over andstop the blood flow. In hemodialysis, it is not uncommon to use five orsix successive gauze compressions over a period of 20-30 minutes untilhemostasis is achieved.

The prior art also discloses non absorbent materials to stop cannulationsite bleeding. One way of accomplishing this was proposed in McRae etal. U.S. Pat. No. 4,233,980, where a pressure bladder made of flexible,non-elastic material and carried on a rigid, floor mounted arm ispressed against a site to produce hemostasis after an arterial puncture.Another way was proposed in Stanulis U.S. Pat. No. 4,182,338 where askin contacting surface as soft as 25 Shore A durometer is part of astrap arrangement around the portion of the body where blood loss is tobe prevented by compression of the skin contacting surface. Another wayis Roth U.S. Pat. No. 5,263,965 which comprises a rigid disc as a manualcompression aid.

Another significant problem with hollow bore needle cannulation iscannulation-induced infection to the cannulation tract and/or vessel.Although the needle is sterilized at the time of manufacture, and ismaintained sterile in its package, needles may become unsterile as soonas its sterility protector is removed. At this stage it is susceptibleto being contaminated by touch or air-borne bacteria. Or, the act ofcannulation may drag into subcutaneous tissues bacteria from the skinsurface or near-surface dermal layers. While the skin is disinfectedwith various chemicals, this is typically a relative rather thanabsolute disinfection, and bacteria will dwell on, or just under, thedead layer of skin cells of the cannulation site. It is known in thefield of thoracic surgery to control infection induced by scalpels andthe like, by laying over the disinfected skin area intended for surgicalcutting a sheet of sterile plastic. This sheet is pressed against theskin, to which it adheres without adhesive. Not only is the outersurface of the sheet a sterile field on which surgical instruments maybe placed without contamination, but the sheet's adherence to the skintends to immobilize bacteria on the skin and under the dead skin cells.Owing to the clarity of the film, it is possible for the surgeon tovisualize the cutting area and cut through the film as he/she surgicallycuts the patient. Thus, no or few bacteria are dragged into the surgicalsite during cutting due to the effect of the sterile sheet. Tegaderm isa brand name of this prior art product.

Besides cannulating patients, needles also cannulate injection sitescarried on medical devices, such as tube sets, drug vials, IV bags andthe like. The prior art injection sites all comprise elastomeric bungsof a hardness not less than about 10 Shore A durometer, and are carriedin typically plastic housings that hold the bung fixed and undercompressive forces both for sealing the space between the bung and thehousing, but also to urge shut the slit caused by a cannulating needle,when removed. Many elastomers are not suitable for injection sitesbecause they either are either cored out when cannulated with a sharp,beveled hollow bore needle, or they leak through the cannulated sliteven in the presence of the compressive forces urged on it by thehousing. It has not been known until now of a resealable, non-coringelastomeric material that did not require a compressive or retentiverigid housing to be effectively resealable after passage and removal ofneedles, including hollow bore sharp needles.

Another problem of injection sites is that they must be manufacturedinto the medical device. For example a dialysis set typically comprisesthree or more injection sites at various locations on the set. Sincemany sites are never used during a particular medical procedure, thecost of manufacturing injection sites in every medical device, when onlya few are used, represents a great monetary waste. It would beadvantageous if a simple, cheap, attachable injection site to medicaldevices could be developed.

DESCRIPTION OF THE INVENTION

By this invention, a supersoft, typically elastomeric, pad or sheet isdisclosed as an improved replacement for gauze squares, and other modesof achieving hemostasis on any bleeding site, whether by cannulationwith needles of any size, or trauma from gunshot wounds and the like.Its action is the same. The typically substantially nonporous andnonabsorbent-surfaced pad stops the bleeding and promotes clotting,being a solid, pore free pad, or a porous pad typically having at leastone, nonporous, skin like surface. The nonporous, skin like surface liesagainst the bleeding site, for hemostasis. The pores, if present, may beclosed cells, or interconnected, open cells if desired, to contribute tosoftness of the pad. “Pores” are spaces in the pad which are largeenough to pass blood or other medical fluid. The pad may be provided ina package in medically clean, or preferably sterile, condition. The padmay, in some embodiments, comprise a pair of opposed, parallel, equallysized major faces, forming a flat sheet, for simplicity of manufacture.

In the case of cannulation with a needle or catheter, the pad is placedagainst the cannulation site either before or immediately after thecannula is removed, and improves on gauze in two major ways. First, itis not absorbent of blood from the bleeding cannulation site, so muchless blood is lost when it is pressed against the cannulation site toseal off the cannulation slit or hole. Second, because the supersoftelastomer can sealingly conform to even the micro nooks and crannies ofthe skin with extremely low or even essentially no applied force, whichforce can be applied manually, or by tape, or any appliance alone or incombination or in serial order, the vessel underlying the cannulationsite is not likely to be damaged or pressed shut. Our lab tests showthat after cannulating an in vitro vascular model with a 15 g needle andmaintaining the fluid pressure within the vascular model at about 80mmHg (the pressure of a strong hemodialysis graft access), a force ofover 200 gms applied to gauze squares over the (now-removed 15G needle)cannulation site incision slows, but does not stop fluid flow out of thecannulation site, thus mimicking clinical experience with gauze. But byusing a pad of supersoft elastomer of a durometer of no more than about50 Shore 00, and preferably less than about 30 Shore 00, we were able toabsolutely stop flow immediately from the cannulation site with only anapplied holding pressure of about 25 gms. Because of the delicate natureof fistulae and grafts, and their tendency to stenose, such reducedforce and immediate cessation of bleeding is a great advance. Thus, thepressure which is applied to the skin by means of the elastomer padshould exceed the blood pressure at at least the cannulation site exit,or the wound site, but it can be below the pressure needed tosubstantially occlude the underlying blood vessel.

The supersoft elastomer's conformal nature at low forces gives it greatadvantage as a pad, to be manually held and applied to a cannulationsite. The elastomer may be clear (transparent) for direct visualizationof the bleeding site underneath the pad without having to remove thepad, as is the case with the prior art. There is a risk in the prior artof removing an opaque, hemostasis appliance before full clotting isattained, causing unnecessary blood loss from the patient.

Durometer measurements made herein are in accordance with ASTM DurometerHardness Standard D2240-03.

Preferably, the pad may be supplied sterile.

The pad may be large enough to cover any size wound. For example, in thecase of gunshot wounds or military trauma, the wound may exceed manysquare inches in bleeding area. Blood loss from such wounds can be sorapid that bleeding must be stopped prior to evacuating a patient to ahospital. One method to do this is to pour a clotting agent directlyinto the wound, for example flaked chitosan. This agent soaks up bloodand provides enhanced surface area for rapid clotting. However, theclotted chitosan is difficult and time consuming to remove, once thepatient is in the hospital, and the clotted blood within the chitosan isnot available for harvesting by any one of the known, autologoustransfusion methods. It is therefore an advantage for a large wound tobe covered by a sheet of the material used in this invention, as itssupersoft nature conforms to the nooks and crannies of the skin and thewound boundaries, requiring little or no applied pressure to sealagainst blood loss, and retaining blood which may be harvested later andreturned to the vascular system. Sheets or pads of this invention can beapplied within the body or wound to seal off bleeding arteries orvessels directly, so as to limit or stop internal bleeding. Because thesheet is preferably clear and self-sealing, medical workers can passmedical instruments through the sheeting without removing it.

This invention relates to a particular form of elastomeric pad which maybe adhered (applied) to the skin of a patient or to the exterior of amedical device (such as a tube or bag wall) at a desired cannulationsite, either prior to or after the actual injection. In someembodiments, the elastomeric pad may be clear, soft and thin enough,typically on the order of 2 to 5 or 7 millimeters, so that thecannulation site of a patient may be palpitated through the alreadyin-place pad prior to cannulation, in order to find an underlying vesselor medical device by touch so as to maintain the sterility of thepatient's intended cannulation site. The elastomeric pad may be coatedwith a medication such as a disinfectant, or it may be applied topre-disinfected skin, or alternatively, to a wall of a medical devicesuch as a solution bag or tubing, before cannulation, or applied afterwithdrawal of the cannula to prevent bleeding without necessarilycontinuing applied, strong external pressure.

As one type of medication, commercially available silver nanoparticlesmay be used, to be incorporated in effective concentration into theformulation of the material comprising the pad (for example from 0.001to 0.1 weight percent). Such nanoparticles do not strongly reduce thetransparency of the pad, so that the pad may have antisepticcharacteristics and remain transparent. Any other desired antiseptic maybe included, for example, alcohols such as ethanol or isopropyl, orother known antiseptics, either applied to the bottom and other surfacesof the pad, or incorporated into the pad material itself for similareffect at the bottom and other surfaces. If desired, a clotting agentmay be similarly applied to the pad.

Upon cannulation, an advancing needle or catheter can if desired passfirst through the elastomeric pad, and then into the skin of the patientor material of the medical device, typically into a vascular system ofthe patient or lumen of the medical device. Upon withdrawal of thecannula, the pad exhibits the surprising property of resealing without acompressive housing, and provides significant suppression of bleeding orfluid leakage, with a consequent increase of hemostasis in a patient (orsuppression of leakage from the medical device), with significantly lessneed for compression to facilitate the hemostasis. Also, the cannulationsite on the skin (or medical device) may be subjected to anti-microbialeffect due to the presence of an antiseptic at the junction between thepad and the skin or medical device. Many suitable anti-microbialantiseptics are quite volatile, and the pad of this invention provides aphysical barrier that increases the term of active disinfection byreducing the evaporation rate of the antiseptic material, such asalcohol. Pores in the pad, if any, can be used to store antiseptic, thusextending the contact time of the antiseptic around the wound as itdiffuses through the pad material to the wound area. Bacteria on orwithin the skin or medical device may also be immobilized by the pad,and thus prevented from being drawn in through the skin or medicaldevice by the advancing cannula. Thus, aseptic conditions can bepromoted during the time that the cannula resides in the skin. Also,hemostasis with less or even virtually no added pressure can be achievedafter withdrawal of the cannula. Then, the elastomeric pad can beremoved when hemostasis has fully taken place, and when it can beexpected that there will be no further spontaneous bleeding.

Thus, reduction of blood loss can be achieved, particularly in thesituation of chronic patients, where access to the vascular system musttake place frequently. This invention can also work with freshcannulation sites or repeat cannulation sites, commonly known as“buttonhole” sites.

It is also of advantage for the elastomeric material of the pad tocontain a liquid plasticizer such as a mineral or other pharmaceuticallyacceptable oil, typically more than fifty percent by weight, so that thematerial of the pad does not significantly adhere to a scab formed bybleeding under the solid bottom of the pad, as the pad rests on the skinof a patient. Thus the pad is easily removed, generally without tearingthe scab after the need to provide hemostasis is no longer present.

Typically, the material of the pad is of approximately the softness ofskin, or softer, which greatly improves the sealing ability, whencompared with other, harder materials.

Accordingly, a method is provided which comprises the method ofsuppressing bleeding through the skin of a patient which comprises:applying to the skin of the patient a soft pad of typically elastomericmaterial having a hardness of no more than about durometer 30 Shore 0,typically no more than durometer 50 Shore 00, to suppress the bleeding.Resealability of the pad to a needle puncture may be provided if thesoft pad is an elastomeric material. However, soft (typically no morethan about Durometer 50 Shore 00), non-elastomeric materials such aspolyethylene foam pads may be used for effective bleeding suppression inthose circumstances where a needle puncture is not used. The elastomeror non-elastomer pad used may either be a solid, pore free pad, or aporous pad typically having at least one, non-porous, skin-like surface,unless the material of the pad is of blood repellant material or thepores are small enough so that blood does not substantially enter intothem, or the pores are separated as in a closed-cell foam, so that thepores may be used to impart softness to the pad, without significantseepage of blood through the pad.

Typically, materials as soft as or softer than Durometer 30 Shore 00 maybe used with good effect.

The soft pad may have a non-porous surface for abutting the skin or awall of a medical fluid container which has the required hardness of nomore than about Durometer 30 Shore 0 or typically no more than Durometer50 Shore 00. Optionally, other portions of the pad may be harder, toprovide support and the like.

If desired, after the soft pad is applied, one may pass a medical needlethrough the elastomeric pad into the tissue of the patient, andthereafter withdraw the needle with substantially suppressed bleeding.

In this circumstance, in some embodiments the elastomeric material ofthe pad may have a hardness of no more than about durometer 30 Shore 00,for example 10 Shore 00 or less.

Alternatively, the needle or hollow cannula may be inserted through apoint of the skin of the patient, and, thereafter, the soft, paddescribed above may be placed on the skin of the patient to cover thepoint of the skin through which the cannula penetrates. Thereafter, thecannula or needle is removed.

Also, a soft, elastomeric pad described above may be applied to the wallof a hollow medical device such as a plastic solution bag. One thenpasses a medical needle through the pad and the wall of the hollowmedical device, and thereafter withdraws the needle, with leakagethrough the hole formed in the wall by the needle being suppressed. Herealso in some embodiments the elastomeric material of the pad may have ahardness of no more than about durometer 30 Shore 00, for example 10Shore 00 or less.

An “elastomer” is defined as a rubbery material having at least onehundred percent elongation to break, and which snaps back tosubstantially its original configuration when released from stretching,like rubber. An elastomer is not a gel, which has little or no abilityto snap back toward an original configuration after stretching.

Further, in accordance with this invention, a method is provided whichcomprises the step of: applying a pad to the skin of a patient or amedical device, the pad consisting essentially of an elastomer or otherflexible material having a hardness of typically no more thanessentially durometer 30 Shore 0, typically no more than about 50 Shore00, and preferably no more than about durometer 30 Shore 00. Preferably,the pad is applied at a pressure, as described above, exceeding theblood pressure at least the cannulation site exit (or the wound site),but below the pressure needed to substantially occlude the underlyingblood vessel. The pressure may be applied by any desired means, forexample manually, until hemostasis has taken place, or by the use oftape that overlies the pad and adheres to the skin, providing downwardpressure, or by the use of straps or bands to tie around an arm or legand thus apply the desired low pressure, or any combination thereofsequentially. Wounds can thus be sealed to stop bleeding, and,similarly, puncture leakage in a medical device can also be stopped.

The material of the pad preferably has a high elongation to break,typically at least about 500% or preferably about 900% to 1000% or more.Such an elastomer exhibits high resealability, so that the needlepuncture hole does not readily leak blood at natural blood pressures,particularly from an artery, vein, or fistula, optionally without acompressive or retentive housing as in the prior art of injection sitescarried on medical tube sets. Also, the elastomeric material, althoughvery soft, tends to be non-coring to conventional medical needles. Thus,a stick-on injection site may be provided by this invention.

In some embodiments, the elastomer pad has a thickness of about 0.1-0.5cm., and has a hardness of no more than about 50 Shore 00 durometer, andpreferably no more than 30 Shore 00, the elastomer material being nonflowable.

In some embodiments, the elastomers of this invention comprise an oilplasticized material such as an oil-plasticized block copolymercomprising (A) at least one crystalline, aryl-containing polymersegment, and (B) at least one elastomeric, aliphatic polymer segment.Some plasticized elastomers of this type are disclosed in U.S. Pat. No.5,508,334 of John Y. Chen, and numerous other patents by the sameinventor, and also in U.S. Pat. No. 5,994,450 of Tony M. Pearce, thedisclosures of which are incorporated by reference herein.

In some embodiments, the crystalline, aryl-containing polymer segmentcomprises monoalkenylarylene polymer units such as styrene oralphamethylstyrene. The elastomeric, aliphatic polymer segment mayconsist essentially of isoprene and butadiene polymer units in someembodiments.

The pad so used may be coated on one side with a skin adhesive anddirectly adhered to the skin, so that preferably the exterior of the padhas no adhesive. Or an adhesive may be mixed into the material, or be abasic attribute of the tacky material. However, in other embodiments,the pad may be carried under a cloth, or a non-woven fabric or plasticstrip, or a length of adhesive tape as in a “Bandaid” (T.M.)arrangement, the elastomer pad being a replacement for the gauze pad ofa “Bandaid” dressing. The strip may preferably carry a hole, thusexposing the pad, which may be transparent, where cannulation isintended. The pad may be carried in or on a single sheet or within amulti-sheet envelope, which envelope also may comprise plastic sheeting,for example, thermoplastic sheets of polyethylene, pvc, polyurethane, orsimilar materials, particularly when the adhesive desired is notcompatible with, or does not adhere well to the elastomeric pad. Thesheet or envelope carries the skin adhesive on one side thereof toadhere the pad to the skin of the patient. The pad may be at leastpartially melted so the material entwines with a cloth or non-woven orplastic material adhered to a strip. Preferably the pad will not detachfrom the skin or medical device until desired. Preferably this adherent,adhesive device will prevent leakage from the cannulation site betweenthe skin (or medical device) and the pad, when the needle has beenremoved.

As stated above, in some embodiments, the envelope, when used, maydefine a central opening to expose the pad carried therein. For example,the envelope may have a pair of opposed, major faces, with each facedefining a central opening, typically aligned with each other, to exposethe pad carried therein.

Some embodiments of the materials used as plasticized elastomers maycomprise a high viscosity poly (styrene-ethylene-butylene-styrene)triblock copolymer having styrene end blocks and ethylene and butylenecenter blocks in a ratio preferably within a range of about 20:80 toabout 40:60, as described in Chen U.S. Pat. No. 5,508,334, column 5. Thepolymer, when blended in a melt with an appropriate amount ofplasticizing oil, may comprise a gelatinous elastomer composition havingin some embodiments a relatively high elongation to break of at leastabout 1600%, and a tear resistance of at least about 300,000 or 500,000dynes per centimeter, with substantially complete, rubbery snap backwhen extended to about 1200% elongation, as called for in the cited Chenpatent. Ultimate tensile strength may in some embodiments be at leastabout 800,000 dynes per square centimeter, having a low elongation setat break of substantially not greater than about two percent.

Other suitable materials are Versaflex CL2003x thermoplastic elastomer,sold by GLS Corporation of McHenry, Ill., and Dermasol DS309 ofCalifornia Medical Innovations, of Pomona, Calif.

Another, currently favored material for manufacturing the pad is the GelConcepts thermoplastic rubber compound, which is a proprietary,oil-plasticized styrene blocked copolymer elastomer manufactured by GelConcepts LLC of Whippany, N.J., particularly Product No. 4125. This is atransparent material, very soft, with a Shore 00 hardness of about 14.

Alternatively, silicone or polyurethane formulations of the propersoftness, with or without plasticizers, may be used.

Surprisingly, it has been found that many of the materials of theabove-cited patents, and other soft materials, exhibit excellent andunexpected hemostatic or leak resistance characteristics when adhered toan injection location such as a patient's skin or a medical device, withthe added advantage that needle coring is suppressed by these materials,despite their softness and resealing of the needle slit despite lackinga compressive housing.

Further in accordance with this invention, a pad of elastomeric materialfor hemostasis may be provided, the pad having a softness of typicallyno more than about durometer 50 Shore 00. The pad further defines, insome embodiments, at least one and preferably a pair of integralretention straps, which are made of the elastomeric material and whichform one piece with the pad, being typically co-molded with the pad. Thethickness of the pad is in some embodiments at least twice, andtypically three or more times, the thickness of the retention straps.

It is preferred for the hardness of the elastomeric material to be nomore than about durometer 30 Shore 00, and for the elastomer to have anelongation to break of at least about 500%.

Such a pad with straps may be used for hemostasis by wrapping the padaround the arm or leg of a patient, overlapping the retention strapsalong a portion of their length. As they wrap around the arm or leg,this overlapping may take place at any circumferential point on the armor leg spaced from the location of the pod. Typically this overlappingtakes place at a diametrically opposed area of the arm or leg from thelocation of the pad. Thus, the pad can be retained in position on theskin of the patient by natural tack adhesion between the retentionstrips. In that position, the pad may provide hemostasis to acannulation site of a freshly withdrawn needle or catheter, and may beretained in position for as long as necessary while providing only alittle degree of compression, and effecting good hemostasis whilepreventing bleeding from the hole in the patient's tissue left behind bythe needle or catheter. This hemostasis can even be effective to causehemostasis in catheter access sites where connection has been made to anartery.

Further in accordance with this invention, a method comprises: insertinga hollow cannula through the point in the skin of a patient and into ablood vessel; thereafter placing a soft, elastomeric pad on the skin ofthe patient to cover the point of the skin through which the cannulapenetrates; and thereafter removing the cannula. The pad in question isas described above, having a hardness of typically no more than aboutdurometer 50 Shore 00, and typically less than 30 Shore 00, wherebybleeding is suppressed by the pad. This method greatly facilitates theprevention of bleeding upon withdrawal of the hollow cannula from theblood vessel, in that, while insertion of the cannula into the bloodvessel can be done conventionally, the pad of this invention can then beplaced over the skin of the patient at the point of cannula penetration,and the high resilience and softness of the elastomeric pad canimmediately suppress bleeding upon withdrawal of the cannula, withoutany significant bleeding taking place while the pad is being appliedafter removal of the cannula.

The soft, elastomeric pad may be affixed to the skin of the patientusing preferably substantially transparent tape.

Furthermore, advantageously, in some embodiments the pad may have araised profile upper surface, for example a solid, frustoconical ordomed shape. The term “dome” or “domed” implies an elastomeric structurehaving a rounded, convex, outer surface. With a raised profile uppersurface, a central portion of the elastomeric pad is substantiallythicker than peripheral portions. Specifically, the central portion maybe at least twice as thick as the peripheral portion of the pad at theedge of the pad. The edge of the pad may have a thickness tapering toessentially zero, or it may connect to an integral strap or outerflange. A purpose of the raised profile is to increase the downwardforce provided by the overlying tape.

Such pads may have a generally flat bottom, to rest on the skin of thepatient surrounding the cannulation or other percutaneous entry site(such as an injury). A slightly concave or convex bottom may betterconform to the curving topography of a cannulation or percutaneous entrysite on an arm or leg. Such a concave or convex shape is deemed“generally flat”. Also, a soft, elastomeric pad of this invention mayhave a raised profile that comprises a convex upper wall which, contraryto previous embodiments in which the convex, upper wall is a dome shape,curving in two dimensions, the curvature of the convex, upper wall mayhave a curvature in only one dimension, so that the upper wall is of ashape of an inverted trough, having substantially similar cross sectionsalong its length.

Thus, such a pad, may comprise oil-plasticized, soft, transparent,elastomer material as previously described, which may be extrudedthrough a die aperture of typically D-shape, for simplicity ofmanufacture.

The pad of this invention, for example the pad of solid, domed shapedescribed above, may reside in a recess defined by a wall of a metal orplastic sheet or other packaging sheet. The sheet also has a flat flangeat least partly surrounding the recess, with the flat flange beingaffixed to the skin of a patient with tape, adhesive, or the like, andwith the recess wall and the patient's skin together enclosing the soft,elastomeric pad, while the pad abuts the skin. The plastic sheet wallwith its recess may comprise a container which is manufactured in amanner similar to known, single-serving jelly containers used inrestaurants, and in which a flat flange surrounding the recess may becovered with a peel sheet which is manually removable, in the manner ofa single-serving jelly container. Also, the flat flange may be affixedto the skin through an adhesive layer carried on the flange.

The metal or plastic packaging sheet may be made of poly(ethylene-vinylacetate), or any other desired plastic material. The recess (such as adome-shaped recess), may be cold formed in the plastic sheet.

Furthermore, as described previously, the hardness of the elastomer maypreferably be no more than about durometer 30 Shore 00, while theelongation to break for the elastomer may preferably be at least about800 percent, and the tear resistance may in some embodiments be at leastone million dynes per cm. Also, the elastomeric pad may have a typicallyglass-smooth, flat face, which may be placed in contact with the skin.

The lower limit of hardness for an elastomer that may be used in apractical manner in accordance with this invention varies to an extentdepending upon the pressure of blood (or fluid in a medical container).Higher pressure fluids generally are better sealed with an elastomerwhich has a hardness that is somewhat greater than may be required inthe circumstance where fluid pressures are lower, although by thisinvention the hardness is no more than about 30 Shore 0, relating tosealing of blood pressure and of the walls of medical fluid containers.For example, a somewhat softer material can desirably be used for thesealing of a venous puncture than may be required for the sealing of anarterial puncture.

In some embodiments, the elastomeric pad may slightly overfill therecess in the plastic sheet, so that an outer portion thereof projectsbeyond the plastic sheet, to provide firm contact with the skin,particularly when the elastomeric pad is placed in contact with the skinwithout removal from the recess of the plastic sheet, to assure goodskin contact. Alternatively, the elastomeric pad may be removed from therecess for use.

Thus, bleeding may be effectively controlled by applying the typicallyelastomeric pad of this invention to a wound, such as at the point wherea cannula is inserted through the skin, using, in some embodiments, asoft pad of elastomeric material having a hardness of no more thandurometer 50 Shore 00, with the pad being of raised profile uppersurface, for example a solid, dome shape with a flat bottom.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a pad of an embodiment of thisinvention.

FIG. 2 is a plan view of a pad of an embodiment of this invention,carried on an adhesive coated sheet of plastic.

FIG. 3 is a transverse sectional view showing the pad of an embodimentof this invention secured in an envelope defined by a pad of plasticsheets, which are normally peripherally secured together, but shown inseparated fashion for clarity, forming an envelope which contains thepad of this invention.

FIG. 4. is a perspective view of a pad of an embodiment of thisinvention placed over a large trauma wound.

FIG. 5 is an elevational view of another embodiment of this invention,showing a pad of frustoconically shaped upper surface with an integralstrap.

FIG. 6 is an elevational view, taken in section, showing a needlepenetrating the skin, with a dome-shaped pad of this invention overlyingthe entrance point of the needle through the skin and secured there byan adhesive sheet member.

FIG. 7 is a plan view of FIG. 6.

FIG. 7A is a modified version of FIG. 7.

FIG. 8 is a perspective view of an elastomeric, dome-shaped pad, carriedin a dome-shaped recess which is defined by a dome wall of a plasticsheet, which sheet also has a flat flange surrounding the dome wall, andshowing a removable peel tab used to enclose the pad until use isrequired.

FIG. 9 is an inverted, sectional view, taken in elevation, of thedome-shaped elastomeric pad of FIG. 8, carried in the dome-shaped recessof the plastic sheet, and shown adhered to the skin of a patient, withthe dome wall of the plastic sheet and the patient's skin togetherenclosing the soft, elastomeric pad.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Referring to FIG. 1, a pore-free pad of very soft elastomer 10 is shown,preferably having a coating of adhesive 12 on its lower face foradhesion to the skin. Pad 10 has a softness of less than durometer 30Shore 00. It can be manufactured in accordance with the teachings ofPearce U.S. Pat. No. 5,994,450, for example comprising apolystyrene-hydrogenated poly (isoprene and butadiene)-polystyrenecopolymer, plasticized with either mineral oil or a combination ofmineral oil and resin. Other suitable materials for manufacture of thepad of this invention are manufactured, for example, by Edizone, LC, aUtah Limited Liability Company of Pleasant Grove, Utah. Other suitablematerials may comprise, for example DS309 Dermasol, manufactured byCalifornia Medical Innovations of Pomona, Calif. Typically, the softness(hardness) of materials used for the pad 10 may be no more than aboutdurometer 60 Shore 000, all according to tests according to the ASTMDurometer Hardness Standard D2240-03, and they may even be so soft as tonot register on the Shore 00 scale and registrable only on an extremelysoft scale according to a “gram bloom” test or the Shore 000 scale. Grambloom involves the applied force necessary to depress a 10 mm diameterflat probe 4 mm into a sample of elastomer.

It is also sometimes desirable for the material used in this inventionto have a tear strength of at least about 800,000 dynes per cm, and anelongation to break of said elastomer of at least about 900%.

Pad 10 may be adhered to the skin 14 of a patient, after the skin hasbeen wiped with an antiseptic such as povidone iodine or an alcohol suchas isopropanol. The pad may be applied while the antiseptic is stillpresent on the skin, so as to trap the antiseptic against the skin. Anyappropriate antiseptic may be used, and the antiseptic may be carried onor in pad 10, if desired. An increased-viscosity or gelled antisepticmay also be used, for example the antiseptic of patent Publication No.US 2003-0175323 A1.

Pad 10 may be of any desired dimension in length and width, blanket sizeto button size, and may be of rectangular shape, or nonrectangularshape, such as circular or oval, if desired. It may have a thickness ofabout 0.2-0.3 cm, which may be thin enough to feel the presence of avein 16 through pad 10 by means of finger touch, because of the extremesoftness of the elastomer material of pad 10. Then, a needle may beinserted in normal manner through pad 10 to penetrate vein 16 for aconventional IV injection process, which may include large volumes ofparenteral solution, blood collection, or extracorporeal bloodprocessing, with the needle penetrating pad 10 at point 18. Pad 10 isdesirably substantially transparent for visualization of the skinunderneath.

When the needle is withdrawn, point 18 recloses, and substantiallyreseals to prevent leakage of blood out of vein 16. Furthermore, suchultra soft material, preferably of relatively high tear resistance (tearstrength of over two million dynes) and relatively high elongation tobreak, is resistant to coring by an injection needle, so that hole 18recloses and reseals, optionally with gentle manual pressure, to anextent sufficient to prevent pressurized blood (or other fluid) leakagethrough hole 18. Also, because of the adhesive attachment of pad 10,little blood leaks transversely from the puncture hole in the skinlaterally between the skin and the adhering material of pad 10.

Alternatively, pad 10 may be applied immediately after withdrawing of aneedle (or catheter) that penetrates the skin, such as a fistula needle,to suppress bleeding. For example, in hemodialysis and otherextracorporeal blood treatment procedures, when a fistula needle iswithdrawn from the patient, substantial bleeding takes place because ofthe larger diameter of fistula needles (and similarly with certain otherextracorporeal blood flow access needles or catheters). Thus, aspreviously described herein, it is normal that special procedures forsuppressing bleeding must take place when those needles and cathetersare withdrawn. By this invention, pad 10 can be used to avoid thosepreviously-necessary special procedures as described above, while alsoresulting in reduced blood loss.

The pad 10 of this invention may be of a small, button-like size ofabout one to six centimeters diameter or the like, particularly when itis desired to suppress the bleeding after withdrawal of a needlelikecannula, whether or not the pad is applied before penetration of thecannula, or after the cannula has been withdrawn. Also, pad 10 may beused to seal larger, laparoscopic catheter holes in a patient, or holeswhich are formed in arterial walls by cardiac angiography catheters,angioplasty catheters, electronic mapping or ablation catheters, and allother medical devices which cause bleeding when they are withdrawn. Acurrent, recommended procedure for the suppression of bleeding after thewithdrawal of catheters and the like from the vascular system ispressure with the use of a sandbag for about three hours. The pad ofthis invention may serve as a substitute for this, being firmly appliedto the resulting wound after withdrawal of a catheter, blockingbleeding, but permitting the patient to be mobile, and suppressing, orpreferably completely eliminating, bleeding.

Instead of using adhesive 12, pad 10 may be applied to the patient inany desired, conventional manner including adhesive tape, a conventionalclamp, a tie around an arm or a leg, or even manually, if that isappropriate.

Furthermore if desired, pad 10 may comprise a relatively large mat orblanket of the soft elastomer material, optionally being thicker thanspecific thicknesses recommended for other uses above, for example athickness of about 0.5 cm or greater, and a length and width each of atleast about 10 cm, to provide a bleeding suppression blanket, tosuppress bleeding from larger wounds such as bullet and knife wounds, orother severe lacerations, providing a mode of first aid to suppressexternal bleeding of an injured patient. The weight of a thicker blanketof the material of this invention can provide sealing force without theneed for added application of pressure, although such added pressure mayof course be applied by any desired means, such as tying the pad to thepatient, or the use of weights or manual pressure. Furthermore, such aform of pad 10, being of relatively greater thickness, such as athickness of 1-5 cm. and being of pillowcase or blanket size, can beprewarmed, to provide a bleeding suppression blanket that can wrap thepatient in whole or in part, and also addresses the issue of shock byproviding positive warmth to the patient. Also, a hot water chamber maybe provided in the pad, like a form of hot water bottle.

Also, when pad 10 is in the form of a thick blanket for bleedingsuppression, it may carry an adhesive on one side for direct adhesion tothe skin of the patient, with the adhesive providing further suppressionof bleeding and migration of blood between pad 10 and the skin, or itsnatural tack may be used to retain the pad blanket 10 on the skin.

Furthermore, pad 10, in all its forms, tends to cause the clotting totake place directly in the needle track or the other injury, with theresult that there are fewer bacteria in the scab which forms, and opensthe possibility of less scarring.

Vitamin E oil and/or another anti-scarring agent or other medicament maybe added to elastomer formulation of this invention, for release to theskin surrounding the injury, and the injury itself, such as the needletrack. Also, other medicaments may be provided to the formulation of pad10, either as a separate layer, or integrally mixed within the materialof the pad itself. For example, clotting agents may be added to promoteclotting, such as collagen.

The material of this invention may contain other agents as well, forexample, clotting (hemostatic) agents such as collagen and other knownmaterials, including simple, inorganic salts and other promoters forblood clotting particularly outside of the body. Other examples ofpossible clotting agents include: Aluminum Ammonium Sulfate, AluminumPotassium Sulfate. Chitosan, Epinephrine, (1:50,000-1:1,000), TannicAcid, Collagen, Styptic Collodion, Hyaluronic Acid, Sodium Hyaluronate,Aluminum Sulfate, Cotarine, Cotarine Chloride, and Cotarninium Chloride.

In some embodiments, the surface of solid, nonporous pad 10 which facesthe skin (or any other surface which is being sealed) may be typicallyglass-smooth, to promote engagement of the ultra soft pad material withirregularities in the skin or other surface, to promote sealing and toprevent the flow of blood or other fluid from the hole being sealedlaterally between the pad and the skin or other surface.

Remarkably, it has been found that the materials of which pad 10 can bemade as described herein generally do not need to be substantiallycompressed to reseal from needle sticks. Thus, while they may be used ina housing, they do not require a housing in many uses, and a housing inwhich they are contained does not have to hold them under compression toobtain desirable results, although such compression may be used ifdesired.

The shape of pad 10 of course is not limited: it may comprise a roundbutton, or a rectangular one of diameter or other transverse dimensionof one or more centimeters, or, as stated above, it may comprise a largeblanket of appropriate size to address severe lacerations, and to atleast partially wrap the patient, being heated if desired to addressshock while also suppressing external bleeding.

Accordingly, a stick-on injection site and/or hemostasis site isprovided, which can be applied when an injection is required, and whichfacilitates aseptic conditions, reducing the drawing of bacteria intothe body as the cannula advances through the skin, and providing goodhemostasis at normal blood pressures.

Alternatively, skin 14 could be a wall of a plastic solution container,a plastic tube, or the like, with the same sealing characteristic beingachieved, providing a penetrable injection site for a needle.

Turning to FIG. 2, pad 10 a, similar to pad 10, is carried on anadhesive plastic strip 20, with adhesive layer 22 on at least a portionof the underside of strip 20 permitting adherence as shown of strip 20and pad 10 a to the skin 24 of a patient, which alternatively maycomprise the wall of a solution bag, or an apertured tubing wall overwhich pad 10 a extends, or the like. Plastic strip 20 can carry adhesiveto adhere to the skin or wall 24. Also, the periphery 26 of pad 10 a canadhere to the same or a different kind of adhesive carried on theunderside of plastic strip 20 to position pad 10 a in fixed mannercovering an aperture 28 formed in plastic strip 20.

Alternatively, FIG. 3 shows an embodiment that looks substantiallyidentical in plan view to the embodiment of FIG. 2, in which anelastomeric pad 10 b is attached to plastic strip 20 b and retainedthere by a peripheral adhesive 30. Also, an optional, additional plasticstrip 32 may serve to form an enclosing envelope by a peripheral sealwith plastic strip 20 b, enclosing elastomeric pad 10 b. Such seals maybe peripheral seals at areas 34. Bottom plastic strip 32 may carry anadhesive layer 36 for adhesion to the skin and an upper, peripheraladhesive layer 38 for retention and positioning of pad 10 b within theenvelope 37 defined between plastic strips 20 b and 36.

Preferably, each plastic strip defines an aperture 28 b, 40 to exposeboth sides of pad 10 b. Pad 10 b, carried within its envelope 37, isexposed for finger palpitation to find a blood vessel under the skin inthe case where adhesion to the skin is desired, and generally for openneedle access through pad 10 b and the wall or patient's skin to whichit is adhered by means of the envelope 37.

Generally, upon withdrawal of a needle, the puncture which is formed inthe respective pads 10, 10 a, 10 b reseals without significantcompression because of the unique physical characteristics of thematerial used as the elastomer.

A specific example of silicone material which may be used to form thepad of this invention is Rhodia 40022 reinforced silicone gel. Softersilicones than this material may also be used, if they retain thecharacteristics of a nonflowing elastomer.

Alternatively, pad 10 may be applied or adhered to the skin byconventional taping, with the center of the pad left exposed for needlepenetration, so that an adhesive layer 12 is not needed. The naturaltack of pad 10 may provide some skin adhesion to seal against bloodflow.

When the elastomeric material is plasticized with a (preferablymetabolizable) lubricating oil, it may be possible to cannulate throughthe pads 10, 10 a, 10 b with a non-siliconized needle, in which theneedle picks up enough lubricant from the disk to desirably reduce theforce of cannulation in a manner comparable with a siliconized needle,to avoid the use of siliconized needles.

As an additional feature, pads 10, 10 a, 10 b may contain enoughimpregnated antiseptic, one such example being isopropanol, so that theinner surface of the pad, lying against the skin, will have an alcoholcontent sufficient for continuing antimicrobial effect. Alternatively, alayer of an alcohol-containing gel may be preapplied to the skin 14, andthen pad 10 may be applied to the skin and, if desired, taped inposition to provide a stick-on injection site. Such alcohol-containinggels are described in Utterberg U.S. Patent Publication US 2003/0175323A1. Or, a porous pad with a solid skin can have the pores filled withalcohol or another antimicrobial agent, for continued antibacterialeffect.

Referring to FIG. 4, a patient 50 who has suffered a severe laceration52 may be treated by immediate care personnel in the field by simplyclosing the laceration and covering it with an enlarged pad 10 c made inaccordance with this invention. Pad 10 c may comprise a soft,transparent elastomer material as described above. A specific materialused for pad 10 c and other pads may be Dermasol DS309, comprising astyrene-ethylene/butylene-styrene copolymer which carries more than 50%of mineral oil as a plasticizer. The particular DS309 material has adurometer of about 20-30 Shore 000, an ultimate elongation (elongationto break) of about 1,000%, and a tensile strength of 800-1200 psi. Amaterial that may be used for pad 10 c (and other pads in accordancewith this invention) may comprise 15-20% ofstyrene-ethylene/butylene-styrene copolymer; 80-85% of mineral oil USP;0.1-0.3% of antioxidant; and 4 parts/per million/of Vitamin E, thisbeing a formulation published for Dermasol by California MedicalInnovations.

Pad 10 c may be of any appropriate shape or size, and may have anydesired thickness, for example, from 0.2 cm. to 1 cm. Pad 10 c has anatural tack so that, if desired, it can spontaneously be retained overthe wound site 52. Alternatively, it may be held by tape or straps, asdesired, to hold blood in the wound site and to promote hemostasis(clotting). If desired, a hemostasis (clotting) agent as described abovemay be applied, or such a hemostasis agent may be carried as a layer onthe inner face of pad 10 c, or may be an ingredient in the elastomerformulation of pad 10 c to leak out into the wound to promote clotting.

Referring to FIG. 5, a pad 56 is shown, being made of an elastomericmaterial in accordance with this invention, such as Dermasol DS309, andfurther defining a pair of integral retention straps 58, 60 which aremade of the same elastomeric material and which form one piece with thepad, having been preferably molded with the pad in a single step. Thethickness of the pad 56 can be seen in this embodiment to be about fiveor six times greater than the thickness of the retention straps. Pad 56,with integral straps 58, 60, may be carried on a relatively stiffbacking strip 62 for storage, from which it may be removed for use.

This pad may be used by being placed on an arm or leg of the patientover a needle or catheter injection site, before or after insertion andwithdrawal of the needle or a catheter introducer device. Then, afterwithdrawal of the needle or catheter, pad 56 can reseal, to facilitatehemostasis, and also it prevents blood leakage.

Pad 56 can be attached by stretching the straps 58, 60 around the arm orleg of the patient, causing portions of the straps to overlap, typicallyat a diametrically opposed portion of the arm or leg from the positionof the pad on the skin. The natural, adhesive tack of the straps canprovide desired adhesion to each other, holding the pad in place on thearm or leg without added adhesive. Alternatively, an adhesive or othertechnique may be used to hold the straps in position.

Referring to FIGS. 6 and 7, a soft, elastomeric pad 70 is of raisedprofile, particularly dome shape, and is made of a soft, elastomericmaterial as described above, preferably having a Durometer of no morethan about 50 Shore 00, and preferably no more than about Durometer 30Shore 00.

In the embodiment shown in FIGS. 6 and 7, needle 72 penetrates the skin74 at point 76, the needle being representative of any desired cannulaused for obtaining access to the body including needles for access tothe vascular system of the patient such as fistula needles.Alternatively, catheters may be used as desired and as discussed above.

In this particular embodiment, before needle 72 is withdrawn,raised-profile, domed pad 70 is laid over needle entrance point 76 ofthe needle into the skin of the patient. A rectangular cover sheet 78,having an inner-adhesive layer 80, overlies domed pad 70, as furtherillustrated in FIG. 7. Basically, sheet 78 is a rectangular section ofadhesive tape or the like, providing gentle, hemostasis pressure to pad70, particularly because of the raised profile of pad 70. Bleeding canstop at once, and the patient is often free to move from the treatmentarea, irrespective of the time of actual clotting. This allows the nurseto treat other patients.

When a rectangular form of adhesive sheet 78 is provided as shown inFIG. 7, a portion 82 of the sheet around needle 72, carried by needlehub 73, may remain open as shown, particularly in FIG. 6, in theimmediate area around the needle so that, after pad 70 has been placedover needle penetration point 76, needle 72 can be withdrawn, and theportion 82 of cover 78 may be manually pressed down onto the skin 74 toprovide a seal of wound 76 caused by the needle and to suppressbleeding.

Alternatively, as shown in FIG. 7A, elastomeric pad 70 may be laid downas shown in FIG. 6 over the wound 76 caused by needle 72, but with thecover sheet 78 a overlying pad 70 being in the form of a narrower stripor strap member, so that at least one edge 84 of pad 70 is effectivelylaterally exposed, without interference by the adhesive tape cover 78 a,so that needle withdrawal 72 is easier, and with less pain.

Other raised profile pads which are not of dome shape may also be usedin this invention.

Turning to FIGS. 8 and 9, an elastomeric pad 70 a of dome shape can fitinto a plastic housing 86, which is formed from a plastic sheet having adome-shaped recess defined by a dome wall 88 of the plastic sheet, withthe plastic sheet also defining a flat flange 90 surrounding dome wall88. The dome wall and recess may also be of other shapes as desired.

A removable peel covering 92 may be conventionally applied to theplastic sheet package 86 to seal elastomeric pad 70 a until the time ofuse.

The basic technology may be similar to that technology which is used tomanufacture single serving jelly containers used in restaurants, exceptthat, in this embodiment, the recess is dome shaped. However, othershapes for container 86 may be utilized, including the conventionalshape of a restaurant jelly container. If desired, an adhesive may beplaced on the outer face of flange 90, to facilitate connection with theskin.

If desired, after opening by peeling away covering 92, soft, elastomericpad 70 a may be removed and placed on the skin in the manner indicatedin FIGS. 6 through 7 a. Alternatively, elastomeric pad 70 a may beretained in container 86 and placed on the skin 74 a along withcontainer 86, as illustrated in FIG. 9. If desired, elastomeric pad 70 amay have a flat face 89 which is slightly elevated above the face offlange 90 when peel layer 92 is removed (as shown in FIG. 8) so that,when placed on the skin 74 a as in FIG. 9, there may be a desirable,slight compression. This compression may be provided by adhesion offlange 90 to the skin or as shown, by the application of tape strips 94to flange 90. Package 86 with its attached, soft, elastomeric pad 70 amay be placed on the skin while a needle is penetrating to cover wound76 or, alternatively, package 86 and/or pad 70 a may be placed on theskin after withdrawal of the needle or other cannula, to cover theresulting wound left behind by the withdrawn needle or cannula. Forexample, a wound from an angioplasty catheter or the like may be coveredby pads 70, 70 a, or a hemodialysis needle wound may be covered by pads70, 70 a.

The plastic sheet of container 86 may be made of poly(ethylene-vinylacetate) (called EVA), polyethylene, or the like. EVA bonds todesirable, plasticized materials that form pad 70 a, and container 86may carry adhesive for adhesion to the skin, and/or may provide a goodconnection with removable cover 92. Also, the poly(ethylene-vinylacetate material) can be cold-formed to form the desired container 86.The pad may typically be easily removable when container 86 is made ofpolyethylene.

As shown in FIG. 9, the recess wall 88 of container 86 and the patient'sskin 74 a together enclose soft, elastomeric pad 70 a, with the padabutting the skin. Container 86 may be secured to the skin by adhesivetape 94.

Pads 70 and 70 a may be made, for example, from Versaflexg CL 2003XThermoplastic Rubber Compound, which is a proprietary, oil-plasticizedstyrene block copolymer elastomer, manufactured by GLS Corp. of McHenry,Ill. This is a transparent material having a Shore 00 hardness of about29, an elongation at break of about 1290% (ASTM D412—Die C, 2 hours at23° C.); a tear strength of about 7 million dynes per cm. (ASTM D624); atensile strength (English) of 280 psi (ASTM D412—Die C—2 hours at 23°C.); a 100% modulus (English) of about 9 psi (ASTM D 412—Die C, 2 hoursat 23° C.) and a 300% modulus of about 15 psi (English) ASTM D 412—DieC, 2 hours at 23° C.). Medicaments, such as clotting agents,disinfectants, or any medically beneficial material may be added to theformulation, if desired.

The pads of this invention may desirably be as clear and transparent asglass so that the wound underneath may be easily monitored withoutremoval of the pad.

Thus, a stick-on injection site or hemostasis device is provided, inwhich the pad through which injection may be made, if desired, does nothave to be retained under compression in a housing to obtain goodresealing, although it may be so retained if desired. Accordingly, thepad-type injection site or hemostasis device does not require a rigidhousing to hold it in a compressed state, but the pad simply providesspontaneous resealing under most physiological blood pressureconditions, thus greatly reducing loss of blood. Such a pad typeinjection site is also usable to provide an injection site through awall of a medical device, while providing good resealing after theneedle is withdrawn. Also, typically larger pads of this invention maybe used for hemostasis of larger wounds.

The above has been offered for illustrative purposes only, and is notintended to limit the scope of the invention of this application, whichis as defined in the claims below.

1. The method which comprises: applying a soft pad to the skin of apatient, said pad consisting essentially of an elastomer having ahardness of no more than about durometer 50 Shore 00; passing a medicalneedle through the pad into the tissue of the patient; and thereafterwithdrawing said needle, whereby bleeding is substantially suppressed.2. A soft, pad of elastomeric material having a hardness of no more thanabout durometer 50 Shore 00, said pad carrying a strap member foradhering the pad to a surface, whereby bleeding or leakage through theskin of a patient or a wall of a hollow medical device may besuppressed.
 3. The pad of claim 2 in which said elastomeric material hasan elongation to break of at least 500 percent.
 4. The pad of claim 3 inwhich the hardness of said elastomeric material no more than aboutdurometer 30 Shore
 00. 5. The pad of claim 2, in which said strap memberis adhesive tape.
 6. The pad of claim 2 which is packaged in sterilecondition.
 7. The pad of claim 2 in which the elongation to break ofsaid elastomer is about 900% to 1000%.
 8. The pad of claim 2 which hasat least one smooth face for contact with the patient.
 9. A flexible,elastomeric hemostasis pad having a non-porous surface for use inpreventing bleeding, said pad having a hardness of no more than aboutdurometer 50 Shore
 00. 10. The pad of claim 9 in which the hardness ofthe pad is no more than durometer 30 Shore
 00. 11. The pad of claim 9 inwhich the pad is made of an elastomeric material which has an elongationto break of at least five hundred percent.
 12. The pad of claim 9 inwhich the pad is packaged in sterile condition.
 13. The pad of claim 9which is substantially transparent.
 14. The pad of claim 9 which has anupper surface with a raised profile, said pad being secured to patient'sskin by adhesive tape or other strap extending over said upper surface.15. The method which comprises: inserting a hollow cannula through apoint in the skin of a patient; thereafter placing a soft, elastomericpad on the skin of the patient to cover with pressure the point of theskin through which the cannula penetrates; and thereafter removing thecannula, said pad having a hardness of no more than about durometer 50Shore 00, whereby bleeding is suppressed by the pad.
 16. The method ofclaim 15 in which the soft, elastomeric pad is held against the skin ofthe patient, with adhesive tape or another strap, and the pad issubstantially transparent.
 17. The method of claim 16 in which the padhas an upper surface is of a raised profile shape.
 18. A soft,nonporous-surfaced pad for hemostasis, said pad having a hardness of nomore than about durometer 50 Shore 00, said pad being carried in arecess defined by a recess wall in a plastic sheet, said sheet alsohaving a flat flange at least partially surrounding said recess wall, tobe affixed to the skin of a patient, with the recess wall and thepatient's skin together enclosing the soft pad.
 19. The pad and plasticsheet of claim 18 in which said pad and recess wall are of dome shape.20. The pad and plastic sheet of claim 19 in which a peel-type closureis affixed to the flat flange to enclose the soft pad.
 21. The pad andplastic sheet of claim 18 in which the flat flange carries skinadhesive.
 22. The pad and plastic sheet of claim 18 in which thehardness of said elastomer no more than about durometer 30 Shore
 00. 23.The pad and plastic sheet of claim 18 in which said plastic sheet ismade of poly (ethylene-vinyl acetate).
 24. The pad and plastic sheet ofclaim 18 in which said pad has a face that projects outwardly beyondsaid recess and plastic sheet.
 25. A soft, hemostasis pad of elastomericmaterial having a hardness of no more than about durometer 50 Shore 00,said pad having an upper wall with a raised profile shape, with a flatbottom.
 26. The soft, hemostasis pad of claim 26, said flat bottomresting on the skin of a patient, and a cover sheet extending over thepad and attached to the skin.
 27. The soft, hemostasis pad of claim 25in which the hardness is no more than about durometer 30 Shore
 00. 28.The soft, hemostasis pad of claim 26, having an elongation to break ofat least 500 percent.
 29. The pad and plastic sheet of claim 28 in whichsaid elastomer has a tear resistance of at least 800,000 dynes per cm.30. The soft, hemostasis pad of claim 25 which includes a medicament.31. The soft, hemostasis pad of claim 25 which is transparent.
 32. Asoft, elastomeric pad, affixed to the skin of a patient, said pad havinga non-porous surface abutting and pressing against the skin of thepatient, and having a hardness of no more than about durometer 50 Shore00; whereby bleeding is substantially suppressed.
 33. The pad of claim32 in which the hardness of said pad is no more than about durometer 30Shore
 00. 34. A soft, nonporous-surfaced elastomer pad for hemostasis,said pad having a hardness of no more than durometer 30 Shore 0, saidpad having a flat face on one side thereof, said pad being carried by awall on a side opposed to said one side, to permit said flat face of thepad to be pressed against the skin of a patient by pressure on saidwall.
 35. The pad of claim 34 in which adhesive tape, or another strap,attached to the skin of the patient, presses said flat face of the padagainst the skin of the patient.
 36. The pad of claim 34 in which thehardness of said pad is no more than about 50 Shore
 00. 37. The pad ofclaim 34 in which said opposed side has a raised profile.
 38. The pad ofclaim 34 which comprises a pair of opposed, parallel, equally sizedmajor faces forming a flat sheet.
 39. The pad of claim 34 in which acannula extends through the pad and the skin of the patient.
 40. The padof claim 34 in which the softness of the pad is about equal to thesoftness of human skin.